Page 1 of 23 | My E-mail appears as spam | The 7 major reasons | Part 5#17
Written by Eyal Doron | o365info.com
MY E-MAIL APPEARS AS SPAM | THE 7
MA JOR REASONS | PART 5#17
In the following article and the next article (My E-mail appears as
spam | The 7 major reasons | Part 6#17), we will review six major
reasons that could lead to a scenario in which E-mail that is sent
from our organization, identified as spam E-mail.
In the current article we will review the following causes:
E-mail content
Violation of the SMTP standards
Bulk\Mass mail
In our journey to become internal \ outbound spam professionals
(unfortunately, at the current time, there is currently no such
university degree), we will need to:
Page 2 of 23 | My E-mail appears as spam | The 7 major reasons | Part 5#17
Written by Eyal Doron | o365info.com
1. Know about the major causes for internal \ outbound spam scenario.
2. Know what troubleshooting tools to use for detects the specific cause.
3. Know what steps need to be implemented for avoiding such causes.
Note – the last major reason for: “My E-mail appears as spam”
is related to the SPF record infrastructure. We will review the
subject of the SPF record in two dedicated articles:
What is SPF record good for? | Part 7#17
Implementing SPF record | Part 8#17
1. E-mail content
Page 3 of 23 | My E-mail appears as spam | The 7 major reasons | Part 5#17
Written by Eyal Doron | o365info.com
A commercial E-mail (Marketing E-mail, mailing list, newsletters, etc.)
that is written improperly, could easily lead to a scenario in which
mail that is sent from your organization, will be recognized and
classified as spam\junk mail. The mail specific content, is one of the
major causes of the internal \ outbound spam problem.
The three major factors, which are responsible for a “problematic
mail content” are:
Specific words, phrases and writing style
HTML coding
Commercial E-mail “rules”
1. Mail content | specific words, phrases
and writing style
Avoid from writing a content that could be recognized as spam.
Page 4 of 23 | My E-mail appears as spam | The 7 major reasons | Part 5#17
Written by Eyal Doron | o365info.com
It’s highly recommended, to learn through about the subject of: how
to write commercial E-mail in the “right way”.
The article: How to Avoid Spam Filters include good examples of E-
mail content, which could be classified as spam or a “spammy
criterion”.
For example E-mail that include one or more of the following
charters:
Using phrases like “Click here!” or “Once in a lifetime opportunity!”
Excessive use of exclamation points!!!!!!!!!
USING ALL CAPS, WHICH IS LIKE SCREAMING AT THE TOP OF YOUR
LUNGS VIA EMAIL (especially in the subject line).
Using bright red or green colored fonts.”
2. Bad HTML coding
Using a “Bad HTML coding” in your commercial E-mail, could lead to a
scenario, which attract attention of spam filters.
An examples for “Bad HTML coding” appear in the excellent article:
Most Common Spam Filter Triggers
1. BODY: HTML has a low ratio of text to image area (1,217 matches)
2. BODY: Message only has text/html MIME parts (971)
3. BODY: HTML has a low ratio of text to image area (729)
4. BODY: HTML and text parts are different (625)
5. Subject is all capitals (324)
6. BODY: HTML and text parts are different (279)
7. BODY: HTML: images with 2400-2800 bytes of words (211)
Page 5 of 23 | My E-mail appears as spam | The 7 major reasons | Part 5#17
Written by Eyal Doron | o365info.com
3. Violation of “Marketing mail rules”|
Use the concept of: “permission-based
emails”
When an organization uses the option of: “marketing mail”, we can
define two major groups:
1. Spam mail or an unsolicited E-mail
2. Legitimate marketing mail described as – permission-based email
marketing (also known as opt-in email). The meaning of: permission-
based email marketing “ is – sending commercial E-mail to people who
have asked to receive them.
When sending a commercial E-mail to a distribution list, the basic
assumption is that this “customer” asks or wants this E-mail
message.
In case that they want to stop getting our E-mails, they will need to
have a way of asking us to stop sending then our E-mail.
One of the most elements that can cause to external organization to
classify your commercial E-mail is -the lack of the “un-subscribe
option” that enable your customers to inform you that they are not
interested in your marketing E-mails.
Additional reading
Permission-based Email Marketing
Permission Based Marketing Policy
Permission Marketing
Opt-in email
opt-in e-mail
What is an Opt-In List?
Email Opt-In: Single Opt-In Versus Double Opt-In
Page 6 of 23 | My E-mail appears as spam | The 7 major reasons | Part 5#17
Written by Eyal Doron | o365info.com
Your E-mail spam score
When your E-mail is reaching to the destination mail infrastructure,
most of the “destination mail systems” will scan and verify the
“integrity” of the E-mail item. For example: a spam filter that will scan
your E-mail items and “stamp” your E-mail with a “spam score”.
The “spam score” is created after the specific mail infrastructure
checks your E-mail message by using different parameters.
Each of the different parameters gets a specific score. In case that
your E-mail item exceeds a certain threshold, your email will be
classified as spam\junk mail and the outcome could be a scenario in
which your E-mail will be deleted by the destination mail server or,
your E-mail will be stamped as “spam mail”, which will lead to the
scenario of: E-mail message goes to the junk folder.
Page 7 of 23 | My E-mail appears as spam | The 7 major reasons | Part 5#17
Written by Eyal Doron | o365info.com
Additional reading
How to Avoid Spam Filters
Most Common Spam Filter Triggers
How to Write E-mail Content to Avoid the Dreaded Spam Filter
Is Your Email Marketing CAN-SPAM Compliant? 7 Common
Mistakes People Make
A Marketer’s Guide to Getting Past Email Spam Filters
What To Do to Avoid Being Flagged as Spam?
Email Tips to Avoid Spam Filters and 9 Top Email Marketing Tools
Avoiding the Spam Folder: Email Marketing Best Practices
10 Tips to Keep Email Out of the Spam Folder
Best practice and recommendation for commercial E-mail
Test your “Marketing E-mail” spam score
In case that you have prepared a commercial E-mail, and you are
going to send this mail to your customer, wait!
Before you hit the “send mail” key, which will send your E-mail to
tens, hundreds or even thousands of recipients, it is highly
recommended that you implement some kind of “spam testing
procedure” that will enable you to get information about the “spam
score” of your specific E-mail message.
Page 8 of 23 | My E-mail appears as spam | The 7 major reasons | Part 5#17
Written by Eyal Doron | o365info.com
There are several “free online services” that will enable you to
examine the marketing E-mail that you are going to send to your
customer.
In the following section, we will demonstrate a nice and interesting
tool: Test the Spammyness of your Emails (https://www.mail-
tester.com)
This web based tool, can help us to get the value of the spam score
and additionally, in case that the “spam test” discovers possible
issues, the information is displayed in easy to understand way.
In the following screenshot, we can see that “spam test” result that
we got by testing a specific E-mail item.
Page 9 of 23 | My E-mail appears as spam | The 7 major reasons | Part 5#17
Written by Eyal Doron | o365info.com
In our scenario, we can see that the score that we got (8 from 10) is
because there are some issues. The “main issue” in our scenario, is
that the organization domain name appears in one blacklist.
When clicking on the “red scare”, we can get a detailed view that
shows us, the list of the blacklist providers was checked + the backlist
provider that registered our domain as blacklisted.
Page 10 of 23 | My E-mail appears as spam | The 7 major reasons | Part 5#17
Written by Eyal Doron | o365info.com
Additional reading
Test the Spammyness of your Emails
Email Spam Checker
Email Spam Test
postmarkapp
Lyris ContentChecker for Email
isnotspam
2. Violation of the SMTP standards
One if the prominent signs for spam E-mail, is an E-mail message
that “violate” SMTP standards.
Spammers use this “violation of the SMTP standards” for covering
their tracks or deceive the destination recipient. For example: by
Page 11 of 23 | My E-mail appears as spam | The 7 major reasons | Part 5#17
Written by Eyal Doron | o365info.com
“declaring” that the E-mail was sent from X while, in reality, the E-mail
message was sent from Y.
The problem is that sometime, even a legitimate organization that
sends a “legitimate commercial E-mail”, could be sent out E-mails
that could look to the destination side, as a “suspicious E-mail” or E-
mail that violates SMTP standards.
A possible example of signs, which can lead to a scenario in which an
E-mail message will be identified a spam\Junk mail could be:
1. From: and Reply To: address is different:
In a “standard” E-mail message, the “From” filed and the: “Reply To”
filed include the same recipient name (E-mail address).
The scenario in which the From: and “Reply To”: address is different,
could be a sign of spam\Junk mail, but at the same time, this is also
very common with the newsletter’s E-mails.
The Message subject contains an E-mail address.
Spammers use this method to mislead the destination recipient and
make him think that the E-mail message is legitimate.
2. Empty To: field:
Spammers use this method because they send bulk E-mail to
hundreds or even thousands of recipients and, they want to hide this
information from the destination recipient.
For this reason, they add the list of the destination recipient to the
BCC field.
Additional reading
How to effectively stop spam and junk mail
Top 10 spam characteristics (#1-5)
Page 12 of 23 | My E-mail appears as spam | The 7 major reasons | Part 5#17
Written by Eyal Doron | o365info.com
The top 10 spam characteristics (#6-10)
FC822: Standard for ARPA Internet Text Messages
3. Bulk\Mass mail
One of the most common risks when sending a commercial E-mail to
a large number of recipients is – that external mail system will
recognize your mail server as a “bulk mailer’s server” and, for this
reason, E-mails that will be sent from your mail server are we
classified as spam\Junk mail.
Q: Does Exchange Online “identify” outbound bulk mail scenarios?
A: The answer is: “Yes”, an Exchange use spam filter that uses a
rating system named: Bulk Complaint Level (BCL) rating.
As far as I know, the method of Bulk Complaint Level (BCL) rating is
used only by “Exchange based mail servers”.
Regarding outbound spam mail, in case that the Exchange Online
recognizes a scenario which can be considered as “bulk mail”, the E-
mail message will be routed to the Exchange Online- High Risk
Delivery Pool and in more critical cases, the Office 365 recipients will
be blocked and will not be able to continue to send Outlook E-mail
messages.
Attached a quote from the Microsoft MSDN blog:
Disabling of offending accounts when they send too much email
marked as spam
Page 13 of 23 | My E-mail appears as spam | The 7 major reasons | Part 5#17
Written by Eyal Doron | o365info.com
Even though we segregate our spam and non-spam into two
separate outbound IP pools, the email accounts cannot send spam
indefinitely. We monitor which accounts are sending spam and if it
exceeds a limit, the account is blocked from sending spam.
[Source of information: Understanding outbound spam controls in Office
365 ]
Additional reading
Bulk Complaint Level values
Take Advantage of EOPs new Bulk Mail Detection
Different Levels of Bulk Mail filtering in Office 365
What’s the difference between junk email and bulk email?
Use transport rules to configure bulk email filtering
Block spam this holiday season with the new enhanced bulk mail
experience in EOP
Q: Can I use Exchange Online as a solution for bulk E-mail?
A: The simple answer is: No!
Let’s start from the end: Office 365 and Exchange Online is not the
“right” infrastructure for implementing a business need of bulk mail.
Technically speaking, the Exchange Online infrastructure “allow” a
maximum of 10,000 mail items per users but, there is an additional
limitation such as the maximum number of mail items per hour and
more.
The “declaration” that Exchange Online is not considered as suitable
solution for bulk E-mail, appear in the public Microsoft article:
Exchange Online Limits
Page 14 of 23 | My E-mail appears as spam | The 7 major reasons | Part 5#17
Written by Eyal Doron | o365info.com
Exchange Online customers who need to send legitimate bulk
commercial email (for example, customer newsletters) should use
third-party providers who specialize in these services.
Another source of information that relates to subjects of bulk E-mail,
appear in the article: Understanding outbound spam controls in
Office 365
b) Use a 3rd party bulk emailer to send the mass communication
There are several 3rd party bulk emailers whose sole business it is to
send bulk email. They can work with customers to ensure that they
have been well emailing practices, and they have resources
dedicated to enforcing it.
The Messaging, Mobile, Malware Anti-Abuse Working Group
(MAAWG) publishes its membership roster here:
http://www.maawg.org/about/roster
Several bulk email providers are on the list and are known to be
responsible Internet citizens.
Note – you can read additional information about this subject in
the article:
Commercial E-mail – Using the right tools | Office 365 | Part 4#17
Q: What could be considered as a suitable solution for bulk E-mail?
A: The simple answer is: using a third party provider, that specialized
in providing a solution of bulk E-mail.
Q: Can you recommend or provide me a name of such bulk mail
providers?
Page 15 of 23 | My E-mail appears as spam | The 7 major reasons | Part 5#17
Written by Eyal Doron | o365info.com
A: You will have to look for yourself for this kind of services. If it
helps, there are websites such as: “Anti-Abuse Working Group
(MAAWG) (https://www.m3aawg.org/about/roster),
which provide a list or “recommended” or well know bulk mail
Page 16 of 23 | My E-mail appears as spam | The 7 major reasons | Part 5#17
Written by Eyal Doron | o365info.com
providers
Page 17 of 23 | My E-mail appears as spam | The 7 major reasons | Part 5#17
Written by Eyal Doron | o365info.com
Additional reading
Exchange Online Limits
Bulk email software
Internal \ outbound spam in Office 365
environment | Article series index
A quick reference for the article series
My E-mail appears as a spam | Article
series index | Part 0#17
The article index of the complete
article series
Introduction to the concept of internal \ outbound spam in general
and in Office 365 and Exchange Online environment
My E-mail appears as a spam –
Introduction | Office 365 | Part 1#17
The psychological profile of the
phenomenon: “My E-mail appears as
a spam!”, possible factors for causing
our E-mail to appear a “spam mail”,
the definition of internal \ outbound
spam.
Page 18 of 23 | My E-mail appears as spam | The 7 major reasons | Part 5#17
Written by Eyal Doron | o365info.com
Internal spam in Office 365 –
Introduction | Part 2#17
Review in general the term: “internal \
outbound spam”, miss conceptions
that relate to this term, the risks that
are involved in this scenario,
outbound spam E-mail policy and
more.
Internal spam in Office 365 –
Introduction | Part 3#17
What are the possible reasons that
could cause to our mail to appear as
spam\junk mail, who or what are this
“elements”, that can decide that our
mail is a spam mail?, what are the
possible “reactions” of the destination
mail infrastructure that identify our E-
mail as spam\junk mail?.
Commercial E-mail – Using the right
tools | Office 365 | Part 4#17
What is commercial E-mail?
Commercial E-mail as part of the
business process. Why do I think that
Office 365\ Exchange Online is
unsuitable for the purpose of
commercial E-mail?
Introduction if the major causes for a scenario in which your
organization E-mail appears as spam
Page 19 of 23 | My E-mail appears as spam | The 7 major reasons | Part 5#17
Written by Eyal Doron | o365info.com
My E-mail appears as spam | The 7
major reasons | Part 5#17
Review three major reasons, that
could lead to a scenario, in which E-
mail that is sent from our
organization identified as spam mail:
1. E-mail content, 2. Violation of the
SMTP standards, 3. Bulk\Mass mail
My E-mail appears as spam | The 7
major reasons | Part 6#17
Review three major reasons, that
could lead to a scenario, in which E-
mail that is sent from our
organization identified as spam mail:
4. False positive, 5. User Desktop
malware, 6. “Problematic” Website
Introduction if the subject of SPF record in general and in Office
365 environment
What is SPF record good for? | Part
7#17
The purpose of the SPF record and the
relation to for our mail infrastructure.
How does the SPF record enable us to
prevent a scenario in which hostile
elements could send E-mail on our
behalf.
Page 20 of 23 | My E-mail appears as spam | The 7 major reasons | Part 5#17
Written by Eyal Doron | o365info.com
Implementing SPF record | Part 8#17
The “technical side” of the SPF record:
the structure of SPF record, the way
that we create SPF record, what is the
required syntax for the SPF record in
an Office 365 environment + mix mail
environment, how to verify the
existence of SPF record and so on.
Introduction if the subject of Exchange Online - High Risk Delivery
Pool
High Risk Delivery Pool and Exchange
Online | Part 9#17
How Office 365 (Exchange Online) is
handling a scenario of internal \
outbound spam by using the help of
the Exchange Online- High Risk
Delivery Pool.
High Risk Delivery Pool and Exchange
Online | Part 10#17
The second article about the subject
of Exchange Online- High Risk
Delivery Pool.
The troubleshooting path of internal \ outbound spam scenario
Page 21 of 23 | My E-mail appears as spam | The 7 major reasons | Part 5#17
Written by Eyal Doron | o365info.com
My E-mail appears as spam –
Troubleshooting path | Part 11#17
Troubleshooting scenario of internal \
outbound spam in Office 365 and
Exchange Online environment.
Verifying if our domain name is
blacklisted, verifying if the problem is
related to E-mail content, verifying if
the problem is related to specific
organization user E-mail address,
moving the troubleshooting process
to the “other side.
My E-mail appears as spam |
Troubleshooting – Domain name and
E-mail content | Part 12#17 Verify if
our domain name appears as
blacklisted, verify if the problem
relates to a specific E-mail message
content, registering blacklist
monitoring services, activating the
option of Exchange Online outbound
spam.
My E-mail appears as spam |
Troubleshooting – Mail server | Part
13#17
What is the meaning of: “our mail
server”?, Mail server IP, host name
and Exchange Online. One of our
users got an NDR which informs him,
that his mail server is blacklisted!,
How do we know that my mail server
is blacklisted?
Page 22 of 23 | My E-mail appears as spam | The 7 major reasons | Part 5#17
Written by Eyal Doron | o365info.com
My E-mail appears as spam |
Troubleshooting – Mail server | Part
14#17
The troubleshooting path logic. Get
the information from the E-mail
message that was identified as
spam\NDR. Forwarding a copy of the
NDR message or the message that
saved to the junk mail
My E-mail appears as spam |
Troubleshooting – Mail server | Part
15#17
Step B – Get information about your
Exchange Online infrastructure, Step
C – fetch the information about the
Exchange Online IP address, Step D –
verify if the “formal “Exchange Online
IP address a
De-list your organization from a
blacklist | My E-mail appears as spam
| Part 16#17
Review the charters of a scenario in
which your organization appears as
blacklisted. The steps and the
operations that need to be
implemented for de-list your
organization from a blacklist.
Summery and recap of the troubleshooting and best practices in a
scenario of internal \ outbound spam
Page 23 of 23 | My E-mail appears as spam | The 7 major reasons | Part 5#17
Written by Eyal Doron | o365info.com
Dealing and avoiding internal spam |
Best practices | Part 17#17
Provide a short checklist for all the
steps and the operation that relates
to a scenario of – internal \ outbound
spam.
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